Atg8-associated regulatory module coordinates autophagy and ubiquitin-mediated proteostasis in Peronophythora litchii

In this study, we identified two PlAtg8-interacting proteins in Peronophythora litchii: the peroxisomal membrane protein PlPex13 and the methyltransferase PlDph5. These proteins form an Atg8-associated interaction module through pairwise interactions and subcellular colocalization.

Functional analyses revealed that PlDph5 is a positive regulator of macroautophagy, as its deletion significantly impairs autophagosome formation and autophagic flux. In contrast, PlPex13 is dispensable for bulk autophagy but is involved in pexophagy-associated turnover and localizes to peroxisomes. Both PlPex13 and PlDph5 are required for normal vegetative growth, asexual reproduction, and pathogenicity of P. litchii.